The present invention generally relates to communications connector assemblies. More particularly, the present invention relates to a multi-position communications connector that is configured to operate in multiple modes for handling multiple signals.
Telecommunication equipment has benefited from the design of electrical plugs and jacks that provide easy connect/disconnect capability between electrical circuits within the telecommunications equipment and, for example, local network wiring. Such plugs and jacks are particularly popular in association with telephone sets, where they were first used, and, more recently, in association with a large variety of peripheral equipment that is connected to telephone lines. The modular plugs and jacks in use today have been standardized insofar as their performance specifications are concerned and also insofar as certain critical dimensions and structural features are concerned. The use of these devices has become so widespread that new houses and other buildings are pre-wired with jacks located throughout the various rooms, as well as in other strategic locations, to accommodate the communication equipment.
Where large numbers of such connections are needed, it is typical practice to route the wires to a central location, such as a communication closet, where, typically, the jacks are mounted on patch panels. An example of such an arrangement is disclosed in U.S. Pat. No. 5,096,439 of J. R. Arnett. In most installations, it is desirable that the jack be compact, and there have been numerous jacks designed to achieve this goal. For example, U.S. Pat. No. 5,096,442 of J. R. Arnett discloses one such compact jack and plug arrangement, which together constitute a compact electrical connector. The compact electrical connector shown in that patent includes a metallic lead frame mounted to a spring block. The lead frame comprises a number of flat elongated conductors, each terminating in a spring contact at one end and an insulation displacement connector at the other end. The insulation displacement connectors are folded around opposite side walls of the spring block and achieve compactness, and the spring contacts are folded around the front surface of the spring block for insertion into a jack frame. The front surface of the spring block includes a tongue-like projection which fits into one end of the jack frame and interlocks therewith.
The ability of connector assemblies to operate well at high frequencies is limited by crosstalk within the assembly components, especially in the plug, and as frequencies increase, so does the limiting effect of crosstalk. In particular, the rate of data flow, which is ever increasing in communications, causes the wiring parts to become, in effect, antennae that both broadcast and receive electromagnetic radiation. This causes different pairs of wires to be electromagnetically coupled together (i.e., crosstalk), which degrades the signal-to-noise ratio and increases error rates.
Numerous arrangements have been proposed for reducing the effects of crosstalk, including connector assemblies that are configured to minimize crosstalk and connector assemblies that comprise crosstalk compensating components in the overall circuit, such as additional capacitance in the jack for nullifying or compensating for crosstalk in the plug. For example, U.S. Pat. No. 5,186,647 of W. J. Denkmann et al. discloses an electrical connector for conducting high frequency signals in which the input and output terminals are interconnected by a pair of metallic lead frames mounted on a dielectric spring block. The lead frames, which are substantially identical to each other, each comprise several flat elongated conductors, which terminate in spring contacts at one end and insulation displacement connectors at the other end. The conductors generally are parallel and close to each other, but at least one conductor of one frame is arranged to overlap at least one conductor of the other frame in a crossover region. As a result, the crosstalk between the conductors is reduced due to the reversal in polarities caused by the crossovers.
Notwithstanding these advances in dealing with crosstalk in connector assemblies, an electrical connector having even less crosstalk would be desirable. It is also desirable to have a connector that is configured to make circuit connections for uses other than crosstalk manipulation in order to provide a greater degree of versatility. The connector assembly disclosed in the aforementioned U.S. Pat. No. 6,244,907, which is assigned to the assignee of the present application and which is incorporated herein by reference in its entirety, comprises a jack that that is configured to mate with two different types of plugs. A first one of the two types of plugs can be inserted farther into the jack than the second one of the two types of plugs. When the first plug is mated with the jack, the contact wires on the plug abut free ends of the contact wires of the jack and cause the contact wires of the jack to deflect toward and come in contact with conductive pads on the wire board. The conductive pads electrically connect the plug contact wires with compensation circuitry on the wire board, which has the effect of reducing crosstalk.
The second plug cannot be inserted as far into the jack as the first plug. The contact wires of the second jack do not come into contact with the free ends of the jack contact wires, and so the free ends are not deflected onto the conductive pads. Hence, the compensation circuitry is not activated. Therefore, either the compensation circuitry is on or off, depending on which type of plug is inserted into the jack, because either contact is made with the conductive pads or not.
Regardless of whether the compensation circuitry is activated or not, the signal path of the wire board is always the same, i.e., the signal path is never through the conductive pads and the compensation circuitry, but is always from the contact wires of the plug through the non-free ends of the contact wires of the jack (i.e., the ends that are attached to the board). Consequently, regardless of the type of plug that is inserted into the jack, the signal path is always the same through the wire board circuitry.
A need exists for a communications assembly comprising a jack that is not only capable of coupling with different types of plugs, but that is also capable of handling different signal types and of processing the signals in a manner dictated by the type of plug that is mated with the jack.
The present invention provides a jack that is configured to mate with at least two different types of plugs. The jack comprises a wire board having first and second signal processing circuits thereon. When a first one of the different types of plugs is mated with the jack, the first signal processing circuit is activated. When a second one of the different types of plugs is mated with the jack, the second signal processing circuit is activated. The first signal processing circuit of the connector assembly includes crosstalk compensation circuitry for reducing or eliminating crosstalk. The second signal processing circuit of the connector assembly preferably does not include crosstalk compensation circuitry.
Certain standard-compliant plugs exhibit a known amount of crosstalk and the jacks with which the plugs are mated normally include crosstalk compensation circuitry for eliminating or reducing the crosstalk. Because these standard-compliant plugs are still in wide use today, a need exists for a jack that is configured to mate with these plugs and that have circuitry for reducing or eliminating the crosstalk in the plugs. However, cables and plugs are currently being designed that exhibit no crosstalk or only a small degree of crosstalk. Therefore, a need also exists for a jack that does not include crosstalk compensation circuitry. If a plug that exhibits a certain amount of crosstalk is mated with a jack that does not include crosstalk compensation circuitry, the connector assembly will not work properly. Similarly, if a plug that does not exhibit crosstalk is mated with a jack that includes crosstalk compensation circuitry, the connector assembly will not work properly.
The present invention provides a connector assembly comprising a jack that is configured with a first signal processing circuit that includes crosstak compensation circuitry and with a second processing circuit that does not include crosstalk compensation circuitry. This allows a single jack to be used with a low performance, standard-compliant plug that exhibits a certain level of crosstalk as well as with a high performance plug that exhibits no, or very little, crosstalk.
The first and second signal processing circuits constitute separate signal paths on the wire board. Thus, when the first plug is inserted into the jack, the signal is operated on in accordance with the configuration of the first signal processing circuitry, and when the second plug is inserted into the jack, the signal is operated on in accordance with the configuration of the second signal processing circuitry. Having separate signal paths on the wiring board of the jack for each different type of plug ensures that the signal will be properly processed.
When the first plug is mated with the communications jack, a first connector assembly is provided that compensates for crosstalk in the first plug. The first plug exhibits a predetermined level of crosstalk for which the first signal processing circuit is configured to compensate. When the second plug is mated with the communications jack, a second connector assembly is provided that does not compensate for crosstalk. The second signal processing circuit does not include signal processing circuitry because crosstalk is substantially absent from the second plug.